Polymethine dyestuffs



Patented June 17, 1952 J "Harry"De1"k Edwards, Ilford, England; assignor t Ilford Limited, llfordf'Elig'land, a- British company No D raw i ng. Application September 22,- 1949, serial No. 117,267. In Great Britain October 20 Claims. 1 This invention relates particularly to "dyestuffs having a substi-tuted methine chain.

- In 'eo pending I application No. -1 17,265; -'fi1ed September I 22,: 1949;. now -Patent -Noi-t 2,534,112,

there is describedthe production of-intermediates of the general formula:

CN R2 oooR sRa V where Rf-and" Rs' are' aikyi groups and R23 an aikyror' ami-K5 1 g reup: As expi'ained in' that: applicationg R13 and R}; may be alkyl groupsleontaining 1 to: 12 carb0natoms such as niethy1=; -ethy1,- hexylg-botyl -and fioficyi groupswand: Ra may be any of suoh alhyi groups or anaralkyl group, e. g. benzyi' onnaphthylmethyl.

-The preferred intermediates according to the said appliatiomnave tne' iormulaz used herein-and m the following claims is to be understood to 'includewthe stereoisomeric form represented by -the said aiternatiye formula.

Where in such intermediates-the group R: is an alkyl or aralkyl group the formula may be re-written:

where R2 is a" hydrogen atoxnor an' alkyi groups to methine dyestuffs and The i GHzgroup in such comp'oundsiihasnbeen found to be reactive and according toathe' present invention dyestuffs areobtained by reacting a compound of the general formula:

where R1; R3 arid- Rg; have the meanings assigned to them above, withan alkyl or -aralkyilqua-temar'y salt of a Twe n!enriberedor six-membered hetero'c'yclic ni-trogen'compound of the igenral formulai where Q represents a thioetherzzgroup of the formula SR6 or an amino or substituted amino (preferably a'cetamino): g10l1p',\R5 represents: an aik yi or -a'ralkjrl: groupb'Rc represents an al-kyl group, e'.- g.-any of those' mentioned"above; X represents an acid radicle, e. g. chloride; bromide, iodide, sulphate or p to1uene lsulphonate, n is nought or one, and D is the residue of a fivemembered or six-merhbe're'd heteroyclic nitrogen nucleus.

The course of the reaction is-believed to be as The residue D may .be; for example, the .residue of any of the types of heterocyclic nuclei comm'onIy employed in photographic rcyanine-v sensitising dyes; e. gv thiazoles, oxazoles, -sel'enazoles and theiripolycyclic' homologues such as those of the benzene, naphthalene, acenaphthene -and anthracene: tseries, pyridine and its polycyclic homoiogues such as 'quinoline' and: wand:- 3 naphthoquinoiines; wlepidines, 'indolenines =diazines such as pyrimidines and quinazolines, diazoles such as thio-BW-diazole; oxazolines, thiazolines and selenazolines. The polycyclic compounds of these 'series'may' be 'sub'stitutedin the carbocycli'c rings by one or'more'groups-suchas alkyi; a'ry1, amino, hydroxy, alkoxy and methylene-dioxy groups or by haibgenatoms.

' The reaction is preferably effected in the presonce of a basic condensing agent, e. g. an organic base such as pyridine or triethylamine. In the case where Q is a thioether group it is convenient to form the heterocyclic compound containing the radicle Q as a step continuous with the pro duction of dyestuffs in accordance with the invention, i. e. to work without actual isolation oi the heterocyclic thioether compound. Thus the quaternary salt of the heterocyclic compound containing a reactive methyl group in a or 7 position to the quaternary nitrogen atom may be reacted with a trialkyl trithio orthoformate in the presence of acetic anhydride and the product, without purification, reacted directly with the compound of formula (b).

The dyestuffs produced according to this invention having the general formula above are valuable sensitisers for silver halide photographic emulsions.

The following examples will serve to illustrate the invention, but are not to be regarded as limiting it in any way:

' EXAMPLE 1 Ethyl 6- (B-eth yZ-Z :3-clihydrobenzthmzolylidene- 2-) 3-ethyZthio-2-cyano-2 :4-hemdienoate 2-w-acetanilidovinyl benzthiazole ethiodide (4.5 gms.; .01 mol.) and ethyl 2-cyano-3-ethylthio-2-butenoate (1.99 gms.; .01 mol.) were boiled together for minutes in cc. pyridine. On standing, 2. black solidseparated. M. Pt. 205 C.

The solid was purified by extraction with ether, the ether extract giving a deep red solution from which mauve crystals separated on concentration, M. Pt. 127 C.

Recrystallisation from methyl alcohol raised the M. Pt. to 149- C. and further crystallisation from methyl alcohol gave mauve needles, M. Pt. 151 C.

This dyestufi, incorporated in a gelatino silver iodobromide emulsion, imparts a band of sensitivity extending to 700 m l with a sharp maximum at 680 m EXAMPLE 2 Ethyl 6- (3-methyZ-tetraitydrothiaaolylidene-2-) 3-ethyZthio-2-cyano-2:4-hexadienoate Methyl thiazoline (2.0 gms.; .02'mol.) was fused with methyl para toluene sulphonate (3.7 gms.; .02 mol.) at 100 C. for hour. Ethyl trithio ortho formate (4 cc.; .021 mol.) was then added and the mixture boiled gently in acetic anhydride (15 cc.) for 10 minutes giving a deep orange solution. The acetic anhydride was distiled ofl? in vacuo and the remaining oil dissolved in ethyl alcohol (50 cc.).

Ethyl 2 cyano 3 ethylthio 2 butenoate (4 gms.; .02 mol.) and triethylamine (3 cc.; .02 mol.) were then added and the whole boiled gently under reflux for 15 minutes giving an orange pink solution.

Dilution with water precipitated an oil which hardened to give mauve crystals M. Pt. 166 C.

crystallisation from methyl alcohol gave M. Pt. 158 C.

This dyestufi, incorporated in a gelatino silver lodobromide emulsion, imparts a band of sensitivity extending to 590 m with a maximum at 560 m EXAMPLE 3 Ethyl 6- (3 methyl 2;3-dihydrobenzoazczolylidene-2-) 3 ethyZthio-Z-cyano-Z:4-hexadienoate I l-w-acetanilido v nyl benzoxazole methiodide (2.1 gms.; .005 mol.) was boiled gently under reflux for 10 minutes in ethyl alcohol (30 cc.) with triethylamine (.76 cc.; .005 mol.) and ethyl 2 cyano 3 ethylthio 2 butenoate (1 gm.; .005 mol.) giving a reddish pink solution. Dilution with water precipitated an oil which hardened on standing to give mauve crystals M. Pt. 205 C. Crystallisation from methyl alcohol gave M. Pt. 210 C. Recrystallisation from methyl alcohol gave M. Pt. 212 C.

This dyestuff, incorporated in a gelatino silver iodobromide emulsion, imparts a band of sensitivity extending to 710 m l. with a maximum at 650 mu.

EXAMPLE4 Ethyl 6 (3 methyl 2:3 dihydrobenzoxazolylzdene 2) 3 ethylthio 2 cyano 2:4 heradz'enoate (alternative preparation) Methyl benzoxazole (7.98 gms.; .06 mol.) was fused with methyl para toluene sulphonate (11.2 gms.; .06 mol.) at C. for 4 hours.

Ethyl trithio ortho formate (12 cc.; .072 mol.) was added and the mixture was boiled gently in acetic anhydride (75 cc.) for 10 minutes giving a deep orange/red solution. The acetic anhydride was then run ofi and the remaining oil taken up in spirit (100 00.). T I

Ethyl 2 cyano 3 ethylthio 2 butenoate (12 gms.; .06 mol.) and triethylamine (9 cc.; .06

' mol.) were then added and the mixture refluxed for 15 minutes giving a deep red/pink solution. Dilution with water precipitated an oil which was washed with petroleum ether and extracted with benzene. The benzene solution was dried over potassium carbonate and the benzene was then run oiT under reduced pressure. ,The remaining oil was taken up in spirit from which mauve crystals, M. Pt. 207 C; separated on standing. crystallisation from methyl alcohol gave M. Pt. 211 C. Second crystallisation from methyl alcohol gave M. Pt. 212 C.

EXAMPLE 5 Ethyl 6-(3 methyl 2:3 dihydrobenethiaeolylidene-2-) 3-ethyZthic-2-cyano-2 :4-heradie1wate Methyl benzthiazole (1.49 gms.; .01 mol.) was fused for 2 hours with methyl para toluene sulphonate (1.86 gms.; .01 mol.). Ethyl trithio ortho formate (2 cc.; .012 mol.) was then added and the mixture was boiled gently for 10 minutes in acetic anhydride (30 cc.) giving a deep orange/red solution. The acetic anhydride was distilled ofi under reduced pressure and'the remaining oil was dissolved in ethyl alcohol (30 cc.).

Ethyl 2 cyano 3 ethyl 2 butenoate (2.0- gms.; .01 mol.) and triethylamine (1.5 cc.; .01 mol.) were then added and the mixture boiled gently for 10 minutes under reflux giving a deep mauve/red solution.

Dilution with water precipitated an oil which EXAMPLE '6" .1 Ethyl 6- (3-ethg Z-tetrahydrothiazolylidene-Z-) 3- ethylthio-Z -cya.no-2 :4 -he:cadienoate Methyl thiazoline (2.0 gms.; .02 mol.) was fused with ethyl para toluene sulphonate (2.0 gms.;

1611 with water iiiecifiitatd art 611 1116B as washed with ne'tioleuni et er a d extracted with benzene. 'Ih be'hzhesolution was af fd ever fietg smn carbonate-enema and ur mer eaueed e tr'iteratec with methyl 51661101 from we crystals. M. Pt. 117 ais'eisa atde' Ciystallisation 'froni methyl alcohl fate ef 'sta s, Ft. 119? c. nee 'st-aiiizahoii ii'fri methyl alcohol gave M. Pt. 120 C.

EXAMPLE '7 Ethyl 6=(-s'-*emijz=2:ei-dihydre 4:5 biiz belie: thiaz ZyZide'ne-2-) -3-ethylthio 2 cyano i 254: fieic'iiiifieate 2 -i nethy1;;8 naphthathiazole (1,005 gmsc .005 mol.) was fused with ethyl para; toluene sulpho nate (1 gm.; .005 mol.) for 12 hours at 160 C.

Ethyl trithio ortho fo'finate' (1 cc.; .0052 mol.) was added and the mixture boiled gently lindf reflux in acetic anhydride' (20 66;) for 20 minutes. The acetic anhydride was then removed by distillation in vacuo. The residual oil was washed with dry etf ie'fand dissolved thyl alcfofil (25 ($6.) with ethyl '2=cy ino-3ethylthio=2butn65t (1' 00511101.). Triethylamine (.75 cc.; .005 11161.1 was added and the fiiixturwa sihfi d gently finder i-jfiuii for miniit'es' giving a deii mauve/blue solution. The solution {wee then slightly diluted and on s'taiidifi dark blue" crystals separated. Pt. 171" C'.

y crystals were e'iitijactd'with en fie Soxhlett'itfactor and the be ne' solutidn gen ceritifated iiiider r'educed resfsure to aboiit. '15 9e.

riis'dyestiifi, incorporated in a. gelatifip suvei iddobroriiidejefnulsion, im'p'afts a band of sensif tiv'ity extending to 730' mp with a inaxiiiiu'iii at 690mg.

.. .w e: 1242191951 7; was boiled g ritly' under' reflux for 10 mmmes g ng 9'; deep meme redeem Orli dilutionf and"ego1 i1"""1ha1ive crystals seiiarated. flirt. 150'? c, e cfysftalswre eitfractedwith hefizenei n'ai Soidilett eiitfa'c'torelnd after donc'em heave .me ee ii eexam dbb 'om de. mul i n n It M tivityeggt'en'ding to 650 mp with a peak ma soliition boiled gently under rfluic forin nutes Dilution with water oi the deep blue solution cipitated an oil which was extracted with I; zene. The Y benzene solution was washed 1 water; dried over potassium carbonate a flilitd m 73 5 15 .1321 9-. A e fie i t eipi e d... g en 9 w M; B1; 1315;? c. Crystallisatio'ri from methyl aloei-(i Ethyl: W 3 igi'ifithyl-I :2-dihydro, indclylidepe 2 3 ethxyZthz'o 2 oywn-o 2:4 hexadienoate (ii-Ethyl thiio vinyl triinet'hyl indoleniiie iiit iic'sg dide (1.7 girls; .005 mohj was dissllved in ethyl alcoholcc.)- with ethiy'l 2fcyano z-but'enoate (0.5 g .005 mo a amine (1.5 66:, .01 r'noly) n The n'Tixtfire wa gently under reflux for 1 0, rninutes giving a mauve/pink some-en. Dilution with water precipitated an oil which hardened amm togiii blue tinted crystals, M. P125117, 0: Th prhduct was extracted with benzene in a Soxh'l-ett 'xtractor and the benzene concentrated under rg" idohrornijde" acumen, 1m arts 61 off in vacuo. The residualoil was washed dry ether and dissolved in ethyl alco ho'rczg cg); Ethyl 2-cyano-3-ethylthio-2-butenoate (1 gm.;

7 .005 mol.) and. triethylamine (.75 cc.; 005 mol.) were added and the mixture boiled gently under .reflux for 10 minutes giving a deep mauve/blue solution. On cooling and dilution with water green tinted crystals separated. M. Pt. 192 C.

The product was extracted with benzene in a Soxhlett extractor and the benzene solution concentrated to about co. in vacuo. Dilution with light petroleum precipitated crystals M. Pt. 192 C. crystallisation from ethyl alcohol gave no increase in melting point.

This dyestufi, incorporated in a gelatino silver iodobromide emulsion, imparts a band of sensitivity extending to 690 m with a flat maximum at about 640 m EXAMPLE 12 Ethyl 6-(3-methyZ-2:3-dihydro-4:5 benz benzthzaz0lyZidene-2-) 3-ethylthio-2 cyaxno 2:4- heradienoate 2 methyl {3 naphthathiazole (1.005 gms; .005 mol.) was fused with methyl para toluene sulphonate (.93 gm.; .005 mol.) at 100 C. for 16 hours. Acetic anhydride cc.) and triethyl trithio ortho formate (1 cc.; .0052 mol.) were then added and the mixture boiled gently under reflux for 20 minutes. The acetic anhydride was distilled off in vacuo. The residual oil was washed with dry ether and dissolved in ethyl alcohol cc.). Ethyl 2-cyano-3-ethylthio-2- butenoate (1 gm.; .005 mol.) and triethylamine (.75 cc.; .005 mol.) were added and the mixture boiled gently under reflux for 10 minutes giving a deep mauve/blue solution. On cooling and dilution with water green tinted crystals separated, M. Pt. 186 C. The product was extracted with benzene in a Soxhlett extractor and the benzene solution concentrated to about 10 cc. in vacuo. Dilution with light petroleum ether precipitated crystals, M. Pt. 199 C. Crystallisation from methyl alcohol gave M. Pt. 202 C.

This dyestuff, incorporated a gelatino silver iodobromide emulsion, imparts a band of sensitivity extending to 740 m l with a sharp maximum at 690 m EXAMPLE 13 Ethyl 6-(3-ethyZ-2:-dihyclro-5-phenyl banana:- az0ZyZidene-2-) -3-ethylthio-2-cyano-2 :4-hemadienoate 2-methyl 5-phenyl benzoxazole (2.09 gms.; .01 mol.) was fused with ethyl para toluene sulphonate (1.99 gms; .01 mol.) for 16 hours at 100 C. Triethyl trithioortho formate (2 cc.; .012 mol.) was added and the mixture boiled gently under reflux in acetic anhydride (20 cc.) for 20 minutes. The acetic anhydride was distilled off in vacuo. The residual oil was washed with dry ether and dissolved in ethyl alcohol (20 cc.) with ethyl 2-cyano-3-ethylthio-2-butenoate (2 gms.; .01 mol.) and triethylamine (1.5 cc.; .01 mol.). The mixture was boiled gently under reflux for 10 minutes giving a deep magenta/red solution. On dilution and cooling mauve crystals separated, M. Pt. 162 C. The crystals were extracted with benzene in a Soxhlett extractor and the benzene solution concentrated to about 10 co. in vacuo. Dilution with light petroleum ether precipitated crystals, M. Pt. 163 C. crystallisation from methyl alcohol gave blue tinted crystals, M. Pt. 164 C.

This dyestufi, incorporated in a gelatino silver iodobromide emulsion, imparts a band of sensitivity extending to 620 m l with a flat maximum at about 580 m 8 EXAMPLE 14 Ethyl 6-(3-ethyl-2:3-dihydro 6:7 benzbenzthiazolylidene-2-) -3-cthylthi0 Z-cyano-ZA-hexadienoate 2 methyl a naphthathiazole (1.005 gms.; .005 mol.) was fused with ethyl para toluene sulphonate (.99 gm.; .005 mol.) at C. for 8 hours. Acetic anhydride (30 cc.) and triethyl trithio ortho formate (1 cc.; .0052 mol.) were then added and the mixture boiled gently under reflux for 30 minutes. The acetic anhydride was distilled off in vacuo. The residual oil was washed in dry ether and dissolved in ethyl alcohol (25 cc.). Ethyl 2-cyano-3-ethyl-thio-2-butenoate (1 gm.; .005 mol.) and triethylamine (.75 cc.; .005 mol.) were added and the mixture boiled gently under reflux for 10 minutes giving a deep mauve/ blue solution. On standing and dilution green tinted crystals separated. M. Pt. C. The product was extracted with benzene in a Soxhlett extractor and the benzene solution concentrated to about 10 co. in vacuo. Dilution with light petroleum ether precipitated crystals M. Pt. 176 C. crystallisation from ethyl alcohol gave M. Pt. 177 C.

This dyestufi', incorporated in a gelatino silver iodobromide emulsion, imparts a band of sensitivity extending to 670 me with a flat maximum at about 650 m EXAMPLE, l5

Ethyl 6 (3 methyl-2:3 dihydrobenzthiazolylidene-2) -3-methylthio-2cyano 2:4 hexadienoate Methyl benzthiazole (.745 gm.; .005 mol.) was fused with methyl para toluene sulphonate (.93 gm.; .005 mol.) for 16 hours at 100 C. Triethyl trithio ortho formate (1 cc.; .0052 mol.) was then added and the mixture boiled gently under reflux for 20 minutes in acetic anhydride (15 cc.) The acetic anhydride was then removed by distillation in vacuo. The residual oil was washed with dry ether and dissolved in ethyl alcohol (20 cc.) with ethyl 2-cyano-3-methylthio-2-butenoate (.925 gm.; .005 mol.) Triethylamine (.75 cc.; .005 mol.) was then added and the mixture was boiled gently under reflux for 10 minutes giving a deep mauve/blue solution, On dilution and cooling blue tinted crystals separated. M. Pt. 167 C. The crystals were extracted with benzene in a Soxhlett extractor and the benzene solution concentrated in vacuo to about 10 cc Dilution with light petroleum ether precipitated dark blue crystals. M. Pt. 169 C. crystallisation from methyl alcohol gave M. Pt. 171 C.

This dyestuff, incorporated in a gelatino silver iodobromide emulsion, imparts a band of sensitivity extending to 730 m with a maximum at 690 m EXAMPLE 16 Ethyl 6 3-methyl-2 .'3-dihydrobenzthiazolyliden- 2-2) -3-methylthio-2-cyano-2 :4 -hezcaclienoate Z-methyl benzthiazole (.745 gm.;' .005 mol.) was fused with ethyl para toluene sulphonate (.995 gm.; .005 mol.) for 16 hours at 100 C. Acetic anhydride (20 cc.) and triethyl trithio ortho formate (1 cc.; .0052 mol.) were then added and the mixture boiled gently under reflux for 20 minutes. Acetic anhydride was distilled oil in vacuo and the remaining oil washed with dry ether and dissolved in ethyl alcohol (20 cc.). Ethyl-2-cyano3-methylthio 2 butenoate (.925 gm.; .005 mol.) and triethylamine (.75 cc.; .005

1 :iodobromide.-emulsion,- imparts aband: of sensitivity-. extending tox1660- m iwith a maximum at a -eboutix620. m

' -;EXA1\/DPLE:17 PYlt'thg/Z 6 (3-m'ethyl-2 :3-dihydro- ,5-benzf-benzthiaaqlylidene 2 3 methyZthio-Z-cyano- 2:.4-;-Zz ea:adienoate v ZQmethyI pmaphthathiazole- (1.005 gms; 005

lmol.) was. fused with methyl .para toluene sul- .phonate. (.93; gm..; .005mo1.) .at140iC. for 6 hours. Acetic anhydride +620 00.); and triethyl, ,trithio or-th-o formate. ('1, cc; ..005 -2-mol.) were added and :thEr mixture. zboiled'flgently under= reflux fr v 20 minutes. The acetic anhydride was distilledmfi in vacuo and the remaining oil washed with dry ether and dissolved in ethyl alcohol, (20 ,cc.). 'Ethyl-2 -cyetno-B-methylthio-j- 2-- butenoate (.925 gm; x005 mol.) and triethylamine (.75 cc.; .005,

mol.) were then added and the mixture boiled .-:--.;g n v-zunder;refiuxror mrmmutes givin a. deep :r; mantle/blue: solution. ;On cooling and dilution .-..-1 rysta1s: separated. M.:Pt. --197 C. The crystals :were gxtracted with benzene; in a SOXhIGtt, ex- ;tractor andithebenzenefiolution concentrated in :vacuo to about 15 cc; iDilution-twith light petroleurn. etherprecipitatedycrystalsM. .Pt.; 229?." C. wstallisationz'from m hyl alcohol gave M. Pt. -.230, C. Y

This dyestumxmcorporatedm a1gelatinosilver ;--'-,i Od0'b,1Qmidev emulsion, imparts a-;band:- of sensil r tv.ext nd ng to about700. mg with a maximum tea-t ab ut 650m.

2;:EXAMP 2emethyl iephenyhbenzoxazole (1.04 .gms.;

T005 mol.) waiiused withmethylpara toluene sulphonate (.93 gm.; .005 mol.) at 100 C. 61 2 hours. Acetic a'nhydride -"(ZO cc.) and triethyl ,wtrithio. ortho-formater (1:90.; .0052 mol.)-Were .eaddedand the .mixtureboiled gently under reflux for 20 minutes. The acetic anhydridetwas dis a tilled oif in vacuo and the remaining oil washed wwithdry ether and dissolved; in ethyl alcohol 20 cc.) Ethyl-Z-cyano-B -methylthip-.2-butenoate ('.925 gm.;- .005 mol.)-- and --triethylamine (475- cc.;' 1 .005 mol.) were then added and themixture boiled gently under reflux for 10 minbutes giving a mauve/pink solution. On cooling andfdilution blueti-ntedcrystals separated. M. Pt. ;182' C. The; crystals were extractedwith '---benzene in a Soxhlett extractor and the benzene tated crystals M. Pt. 199 C. Crystallis ation -from methyl alcohol gave" M. Pt, 204 C. Hecr'ystallisation from methyl alcohol gave M. Pt: i 206 C.

' This'dystuff, incorporated in a gelatino silver iodobromide emulsion, imparts a sensitivity ex- ...tndihg-toaborit 690 m twith a maximum at about 6'70 m 2; methyl dioxymethylene :henzthiazole: (.975

. -gm., ,00 5.-mo1.) was zfused vvith methylpara toluene, sulphonate 1.93" gm. 4.005 mol.). .i'or thours at 120,?v C. .yAcetic-anhydrideiZO cc.) and .triethyl ;,;trithio ortho =formatei (1; cc.;.- ;.0052- mol.);;.were 1'." th nadded and the mixture boiled gentlysunder ;-,-re,flux for 20v minutesr The acetic anhydride was :;;distilled=-;1ofi:.. invacuo. and the. remaining; oil washed. :with dry :ether and 1 dissolved inqethyl aalcohol: (20,160.) 1Ethyl-2-cyanoe3-methy1thi0- :..2,-hutenoate. (.925 gm.;:-.:.005;mol.) and triethyl- .aamine; 1175. cc.;:1.005 mol.) .were ..then 'addedeand ri-the,mixturenboiled gently underlreflux for. 10 minutes giving a mauve/bluesolution. On-v cool- .ing. and. dilution bluetinted crystals separated. .-'M-.Pt..2l6 C; :The crystals .wereextracted with benzene in .a Soxhlett' extractor and thexbenzene solution concentrated in vacuoto: about 15 cc. i'zzDilution with light petroleum ether precipitated -crystals:'M:Pt.1253 C-. Crystallisation from-ethyl alcohol did not raise the melting point. e

.1 E M E? 20 Ethyl 61-;(3 methyl 2:3 :di k '9-5 T. 3O benzoxazolylz'dene 2-) -3-methylthio\ -2:4- hea;adienoate I 2 I ,1 tr m ih ;tb eeexaz iii- 1. 0 was fus w th methykp ratplqen $11 ---n e-- -9 im-. .5m 9-2atl -Gri e v t ylri h o; r Q I a e 52, inc .was then added andjh tyre ;hoiled ;g ently under refill); -fs1r.:- .=;.m; 11ie$ naQe iQ-a hydr (101cm) T e a e iean yfl demw dist l nwaq and th m ini 11; es dywi d 40 ether-and .dissolveda thylalcohol .(10;cc.). t -Em e rmeth h wzzbut nqa m? 0 .51, .1 0 endmtr eih amm ,;-'m e e1 n-add dtensla he. mixtu e bai e r. ref ux: I Q-.:.-minu s 1 e i a ,mauye/pinksolution; On cqol-ingand d lution z r-ys als.s ara e e;.M--.:Pt-; 1 6: ys e e e t a=t wi hcb nzenei a QXl11 21l.:-' trac .a drt e benze e so u n-ew s conce rat o tm c und rer c d; ress me iluti n ishtap 31 1 i r' e i t crystals M. Pt. 155; C..;;Qrystallisationqifrom methyl alcohol gave. Pt. 157 C.

; EXAMPLE. 21

r 1-Ethyl .6 (L-methyl 1 :2 :clihydro-quinolylidenc- 4-)-3-methylthio-2-cycmo-2:4-hexadienoate Lepidine (1.43--gms.; .01 mol.) wa slfused-vyith methylparatoluene sulphonate (1.86 gms; .01 mol.) for '8 hours at 120 C. -Acetic anh y dride (20-00.) and*triethyltrithio ortho formate (2 cc. -.012- mol.) were added and the mixture hgiled gently under reflux for 20 'minutess The acetic anhydridewas distilled off in vacuo-and the re- -maining oil washed with dry ether and dis solved in ethyL al'cohol (20' cc.). Ethyl--2 -cyano-3- methylthio-2-butenoate- (-1.85; gms.;' -'.01;-mol.) andtriethylamine (1.5 00.; -.01 mol.)- were then added and the mixture A boiled gently under reflux for 10 minutes; giving a deep blue solution. On coolingand dilution-an oil separated. "The 'oilwasextracted with benzene and the benzene solution concentrated in -vacuO to about 15 cc. Dilution with light petroleum ether precipitated crystals Pip-.452 C.--;Crystallisation from methyl-alcohol gave M. Pt; 154 C.

- cyano-3-isopropylthio-2-butenoate and dissolved in ethyl alcohol (10 cc.)

- 1 1 EXAMPLE 22 Ethyl-fi-(3-methyl 2:3 dihydrobenzthiazoylidene-2-) -3-n.butyl-thio 2 wane-2:4 hemadz'enoate Methyl benzthiazole (.298 gms.; .002 mol.) was fused with methyl para toluene sulphonate (.364 gms.; .002 mol.) at 100 C. for 4 hours. Triethyl trithio ortho formate (.4 cc.; .0021 mol.) and acetic anhydride cc.) were added and the mixture boiled gently under reflux for 10 minutes. The acetic anhydride was distilled ofi in vacuo and the residual oil washed with dry ether and dissolved in ethyl alcohol (10 cc.). Ethyl-Z-cyano-3-n.butylthio-2-butenoate (.545 gms.; .002 mol.) and triethylamine (.3 cc.; .002 mol.) were added and the mixture boiled gently under reflux for 10 minutes giving a mauve/blue solution. On cooling and dilution blue tinted crystals separated. M. Pt. 140 C. The crystals were extracted with benzene in a Soxhlett extractor and the benzene solution concentrated to about cc. under reduced pressure. Dilution with light petroleum ether precipitated crystals M. Pt. 146 C. Crystallisation from methyl alcohol gave M. Pt. 147 C.

EXAMPLE 23 EthyZ-G-(B-methyl 2:3 dihydrobenzthiazo ylidene-2-)-3-isopropyl-thio 2 cyano-ZA-butenoate Methyl benzthiazole (.298 gm.; .002 mol.) was fused with methyl para toluene sulphonate (.364 gm.; .002 mol.) at 100 C. for 4 hours. Triethyl trithio ortho formate (.4 cc.; .0021 mol.) and acetic anhydride (10 cc.) were added and the mixture boiled gently under reflux for 10 minutes. The acetic acid was distilled ofi in vacuo and the residual oil washed with dry ether and dissolved in ethyl alcohol (10 cc.). Ethyl-2- (.426 gm.; .002 mol.) and triethylamine (.3 cc.; .002 mol.) were then added and the mixture boiled gently under reflux for 10 minutes giving a mauve/blue solution. On cooling and dilution blue tinted crystals separated. M. Pt. 144 C. The crystals were extracted with benzene in a Soxhlett extractor and the benzene solution concentrated to about 15 cc. under reduced pressure. Dilution with light petroleum ether precipitated crystals M. Pt. 148 C. crystallisation from methyl alcohol gave M. Pt. '149 C.

EXAMTPLE 24 EthyZ-6-(3-methyl 2:3 dihydrobenzthiazoylidene-2-)-3-benzylthio 2 cyano- 2:4 -hea:adienoate Methyl benzthiazole (.298 gm.; .002 mol.) was fused with methyl para toluene sulphonate (.364 gm.; .002 mol.) for 4 hours at 100 C. Triethyl trithio ortho formate (.4 cc.; .0021 mol.) and acetic anhydride (10 cc.) were added and the mixture boiled gently under reflux for 10 minutes. The acetic anhydride was distilled off in vacuo and the residual oil washed with dry ether Ethyl-2- cyano-3-benzylthio-2-butenoate (.524 gm.; .002 mol.) and triethylamine (.3 cc.; .002 mol.) were then added and the mixture boiled gently under reflux for 10 minutes giving a mauve/blue solution. On cooling and dilution blue tinted crystals separated. M. Pt. 154 C. The crystals were extracted with ether in a Soxhlett extractor. On cooling the ether solution crystals separated. M. Pt. 160 C. Crystallisation from methyl alcohol gave M. Pt. 161 C.

12 EXAMPLE 25 V M ethyl-6-(3-methyl 2:3 dihydrobenzthiazoylidene-Z-l 3-ethyZthio-2-cyano -2:4- hexa'dienodte Methylbenzthiazole (.745 gm.; .005 mol.) was fu'sed'with methyl para toluene sulphonate (.93

gm.; .005 mol.) at C. for 4 hours. Triethyl trithio ortho formate (1 cc.; .0052 mol.) was added and the mixture boiled gently .under reflux for 10 minutes in acetic anhydride (20 cc.)

The acetic anhydridewas distilled 'off in vacuo and the residual oil washed with dry ether and dissolved in ethyl alcohol (20 cc.). Methyl-2- cyano-3-ethylthio-2-butenoate (.925 gm.; .005

mol.) and triethylamine (.75 cc.; .005 mol.) were added and the mixture boiled gently under reflux for 10 minutes giving a mauve/ blue solution. On cooling and dilution blue tinted crystals separated. M. Pt. 193 C. The crystals were extracted with benzene in a Soxhlett extractor and the benzene solution concentrated under reduced pressure to about 15 cc. Dilution with light petroleum ether precipitated crystals M. Pt. 198 C.

Crystallisation from ethyl alcohol gave M. Pt.

EXAMPLE 26 M ethyl-d-(Ii-methyl 2:3 dihydrobenethzazoylidene-2) -3-methylthio 2 cyano- 2:4 -hea:adienoate Methyl benzthiazole (.745 gm; .005 mol.) was fused with methyl para toluene sulphonate (.93 gm.; .005 mol.) for 4 hours at 100 C. Triethyl trithio ortho formate (1 cc.; .0052 mol.) was added and the mixture boiled gently under reflux for 20 minutes in acetic anhydride (20 cc.). The acetic anhydride was distilled ofi in vacuo and the residual oil washed with dry ether and dissolved in ethyl alcohol (20 cc.) Methyl-2- cyano-3-methylthio-2-butenoate (.855 gm.; .005 mol.) and triethylamine (.3 cc.; .005 mol.) were then added and the mixture boiled gently under reflux for 10 minutes. On cooling and dilution blue tinted crystals separated. M. Pt. 196 C. The crystals were extracted with benzene in a Soxhlett extractor and the benzene solution con- EXAMPLE 27 M ethyl-fi- (3 methyl-2:3-dihydrobenzoa:azolylidene-2-) -3-ethylthio-2-cyano 2 :4 hexadicnoate Methyl benzoxazole (.665 gm. .005 mol.) was fused with methyl para toluene sulphonate (.93 gm.; .005 mol.) at 100 C. for 4 hours. Ethyl trithio ortho formate (1 cc. .005 mol.) was added and the mixture boiled gently under reflux for 20 minutes in acetic anhydride (20 cc.) The acetic anhydride was distilled off in vacuo and the residual oil washed with dry ether and dissolved in ethyl alcohol (10 cc.). Methyl-2-cyano-3-ethylthio-Z-butenoate .925 gm.; .005 mol.) and triethylamine (.75 cc.; .005 mol.) were added and the mixture boiled gently under reflux for 10 minutes giving a mauve/pink solution. On cooling and dilution blue tinted crystals separated. M. Pt. 167 C. The crystals were extracted with ether in a Soxhlett extractor and the ether solution concentrated to about 20 cc. when crystals separated. M. Pt. 171 C. Crystallisation from methyl alcohol gave M. Pt. 172 C.

' 13 .ziAnalogous 'compounds'may beimade by st'rictly similar processes starting with 2-methyl1selenazoline or 2-methy1 oxazoline, withZ-methyl benzselenazole or with Z-methyl pyrimidine or Z-methyl quinazoline. In each case the quaternary salt may be an alkyl, e. g. methyl, ethyl or higher alkyl orbenzyl iodide, chloride, bromide, hydrogen sulphate or p-toluene sulphonate.

v What I claim is:

1'; Process for the production of'methine" dyestulTs which comprises reacting a; compound of the general formula:

OH R,

.:"wher'e R1 isan' alkyl group,- R3 is selected from 'the'class'consisting' of alkyl and aralkyl groups and R4 is selected from the class consisting of the hydrogen atom and alkyl groupspewith a compound of the general formula:

"where Q isselected from theclaseconsisting of thehydrogenatom and alkyl. groups; :with a pound of the gene'ralformula heterocyclionitrogen :nucleusof thetype: used the thioether group" SR6 WhGl'eRo is an alkyl group and amino and acetamino groups, R5 is selected from the class consisting of alkyl and aralkylgroups, X is an acid radicle, n is selected from nought and one and D is -the-- residue of a heterocyclic nitrogen nucleus of: the type used in cyanine dyes. v

2. Process for the production of methine dyestuiis. which comprises reacting a vcompound of thegeneral formula:

O O R1\S Rs where R1 is' an alkyl group, R3 is selected from the class consisting of alkyl and aralkyl groups and R4 is selected from the class consisting of comwhere Q is selected from the class'cons'isting of the thioether group SR6 whereRe is an alkyl :group and amino and-'acetamino groups, R5 is selected from the class consisting of alkyl and aralkyl groups, X is anacid radicle, n is selected .from -nought and one and D is the:residue of a where Rsand R5 are selected from the-class consisting of alkyl and aralkyl groups, R1 is an alkyl group, R4 is-selected from-the-class consisting of the hydrogen atom and alkyi grou-ps,-n.is selected from nought and one-"and D is the residue of a in cyanine dyes.

I .2;6OD3380 4'; Process :for itheproduction oismethinedyestuffs of the generalrformula:

which ecomprises creactingr an --a;lkyl= =2-:cya=rio-3- lkylthio-2 ebutenoate :with a -*;21+thioether-rvinyl benzthiazole quaternary salt alkyl b cheatingzthe -ireagentsltogether in the presence of :abasic condensing agent.

5. Process for the production ofemethine dyestuffs of the general formula:

- ewhich comprisesareacting an alkyl .2 -.cyano-3- alkylthio-Z-butenoate with a 2.-.thioether-l;y inyl quinoline: quaternary-. salt ralkylby heating the reagents together in the presence of 'a-abasic densing agent.

6. Process for the production of methine dyestufis of .thegeneral iformulaz r-which"comprises reacting-2.: ant l'kyl 2'-;oyari'o-3- alkylthio-2-butenoate.iwith a: athioetheniwinyl t. :benzoxazole quaternary .xsaltcalkyl' by heating the 'eagents :together': urn-the? presence: of 'atni'iasic ..-:condensingt\agent. 1

'7. Process for the production of methirretdyestufis of the general formula:

which comprises reacting an alkyl 2-cyano-3- alkylthioQ-butenoate with a- Z-thioether. vinyl naphthathiazole uaternary Lsalt' alkyl by? heatingthe reagents together in the-presence of a basic condensing agent.

8. Process for the production ofrnethinedyestuffs of. the general vformula:

which comprises reacting an alkyl 2='cyano-3- ethylthio-Z-butenoate with a 2 thioetheriviny1 benzthiazole quaternary salt alkyl by heating the reagents ztogether in .zthe'presence of raiihasio con- :-.':den,sing: agent. 7 I e 9. Process for the production of methine dyestufis of the general formula:

SC1H5 (Joe-an alkyl which comprises reacting an alkyl 2-oyan0-3- ethylthio-2-butenoate with a 2-thioether vinyl quinoline quaternary salt alkyl by heating the reagents together in the presence of a basic condensing agent.

10.. Process for the production of methine dyestufis of the general formula:

I 80111 c OOalkyl alkyl which comprises reacting an alkyl 2-cyano-3- ethylthio-Z-butenoate with a 2-thioether vinyl benzoxazole quaternary salt alkyl by heating the reagents together in the presence of a basic condensing agent.

11. Process for the production of methine dyestuffs of the general formula:

alkyl which comprises reacting an alkyl 2-cyano-aethylthio-Z-butenoate with a 2-thioether vinyl naphthathiozole quaternary salt alkyl by heating the reagents together in the presence of a basic condensing agent.

12. An alkyl 2-cyano-3-alkylthio-2:4-hexadienoate containing in the 6-position the residue of a benzthiazole nucleus. having the general formula:

13. An alkyl 2-cyano-3-alkylthio-2:4-hexadienoate containing in the 6-position the residue of a benzoxazole nucleus having the general formula:

s ilkyl 14. An alkyl 2-cyano-3-alkylthio-2:4-hexadienoate containing in the 6-position the residue of a naphthathiazole nucleus having the general formula:

1.5.An alkyl 2-cyano-e3-alkylthio-2z l-hexa dienoate containing in the 6-position the'residue of a quinoline nucleus having the general formula:

z ilkyl 16. Ethyl 6-(3-methy1-2z3-dihydro 5 phenyl benzoxazolylidene -2-) -3-ethylthio-2-cyano-2 4- hexadienoate having the formula:

- 17. Ethyl fi-(l-ethyl 1:2 dihydro quinolylidene-2-) 3-ethylthio-2-cyano-2 4 hexadienoate having the formula:

19. Methyl B-(S-methyl 2:3 dihydrobenzthiazolylidene-2-) -3-ethylthio-2-cyano 2:4 hexadienoate having the formula:

20. Methyl-6-(3-methyl 2:3 dihydrobenzoxazolylidene-2-) -3-ethylthio-2-cyano 2:4 hexadienoate having the formula:

I SO H; GOOCHs N HARRY DEREK EDWARDS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,166,736 White et al. July 18, 1939 2,263,749 White et al. Nov. 25, 1941 2,322,015 Hamer et a1. June 15, 1943 2,340,882 Kendall Feb. 8, 1944 2,342,546 Kendall Feb. 22, 1944 2,353,164 Kendall et a1 July 11, 1944 2,511,210 Kendall et al Jan. 13, 1950 OTHER REFERENCES Chemical Abstracts 1623101 (Abstract of Brit. Med. Journal, 1922 I 514515).

Chemical Abstracts 19:530 (Abstract of Proc. Roy. Soc., London, 963, 317-333, 1924) 

1. PROCESS FOR THE PRODUCTION OF METHINE DYE STUFFS WHICH COMPRISES REACTING A COMPOUND OF THE GENERAL FORMULA; 